Current medical devices that are used for the removal of occlusions, such as thrombi from the vessels (such as those in the brain), have limitations that reduce their effectiveness, reliability, and ease of use. For example, current devices are designed exclusively for the vascular system, and may not be used for extraction of material from ducts, ureters, urethra, or other anatomical features. Current devices are not appropriate for use in large vascular structures such as aorta, vena cava and many peripheral vascular applications, and often do not work well with calcified, organized material due to inability of the wire structures often used to compress into the embolic material prior to an attempted extraction. Current devices often have a wire structure that must incorporate into a thrombus to remove a clot and provide poor distal protection from secondary emboli during thrombus extraction due to open ended stent retriever or partial grasping of thrombus. This may result in an intended thrombectomy procedure causing distal clot embolization and occlusion of previously patent arterial branches and collaterals. Current devices may be less effective when used with associated arterial stenoses due to device collapse and tendency for a stenosis to strip and debride thrombus from device as it is retracted through the stenotic vessel segment. Current devices often require operators to choose a predetermined device length at time of device insertion, but the chosen device length might not match the size of the target thrombus once the operator is in the vessel and provided a closer view of the target thrombus.
Current catheter-based methods and systems for the removal of foreign bodies from an artery, duct, ureter or other interior physical space, often require multiple co-axial (or concentric) sleeves or delivery catheters, some of which are intended for placement on the proximal side of an occlusion, some for direction through the occlusion for placement on the distal side of the occlusion, and still others for holding inflatable balloons, thrombus removal devices and the like. The presence of multiple catheters increases manufacturing complexity and cost, in addition to increasing complexity of usage during an intervention, with greater moving parts and the required ordering of operation aligned with the function of the multiple catheters. Current catheter-based methods and systems are also manufactured and deployed in the clinical setting with a specific catheter, meaning that if during an intervention a clinician wants to deploy (“load”), for example, a retrieval device having a different size than that first deployed in a vessel, the entire catheter-based tool must be withdrawn and a new catheter-based device with the preferred diameter loaded inserted. Additional limitations of the current catheter-based systems include, but are not limited to, a reliance on fixed-diameter instrumentation and/or inflatable bodies (e.g., balloons) for encapsulation of a foreign body or occlusion. As an example, catheters using an inflatable balloon for a distal body and/or proximal body may require that an interventionist pre-select a balloon model and size prior to entering a vessel or cavity because inflatable balloons have a manufactured minimum and maximum inflation diameter. Thus, if the incorrect balloon size is selected, or the clinical setting requires flexibility in the expansion or contraction diameter of the distal or proximal bodies, the intervention may be interrupted to allow for size adaptation of equipment. Incorrect sizing may also increase the likelihood for negative clinical sequelae, such as embolization and release of occlusive matter if, for example, distal protection is lost.
Therefore, there is a need for methods and systems of thrombus, or other matter, removal in which an object targeted for removal may be dynamically surrounded by a retrieval device, rather than incorporated into the target object, wherein the retrieval device can surround the target and may be physically adjusted to match the size of the target object while within the vessel or other cavity.